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Blame SOURCES/kvm-qcow2-Validate-active-L1-table-offset-and-size-CVE-2.patch

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From fdbe21cc29a983e05b6df725a75b1a1b15d7795e Mon Sep 17 00:00:00 2001
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From: Kevin Wolf <kwolf@redhat.com>
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Date: Tue, 25 Mar 2014 14:23:32 +0100
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Subject: [PATCH 25/49] qcow2: Validate active L1 table offset and size (CVE-2014-0144)
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RH-Author: Kevin Wolf <kwolf@redhat.com>
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Message-id: <1395753835-7591-26-git-send-email-kwolf@redhat.com>
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Patchwork-id: n/a
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O-Subject: [virt-devel] [EMBARGOED RHEL-7.0 qemu-kvm PATCH 25/48] qcow2: Validate active L1 table offset and size (CVE-2014-0144)
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Bugzilla: 1079455
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RH-Acked-by: Jeff Cody <jcody@redhat.com>
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RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079455
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Upstream status: Embargoed
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This avoids an unbounded allocation.
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Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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---
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 block/qcow2.c              |   16 ++++++++++++++++
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 tests/qemu-iotests/080     |   18 ++++++++++++++++++
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 tests/qemu-iotests/080.out |   11 +++++++++++
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 3 files changed, 45 insertions(+), 0 deletions(-)
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diff --git a/block/qcow2.c b/block/qcow2.c
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index 8c74dea..8be82f0 100644
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--- a/block/qcow2.c
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+++ b/block/qcow2.c
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@@ -641,6 +641,13 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
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     s->nb_snapshots = header.nb_snapshots;
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     /* read the level 1 table */
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+    if (header.l1_size > 0x2000000) {
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+        /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
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+         * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */
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+        error_setg(errp, "Active L1 table too large");
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+        ret = -EFBIG;
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+        goto fail;
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+    }
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     s->l1_size = header.l1_size;
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     l1_vm_state_index = size_to_l1(s, header.size);
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@@ -658,7 +665,16 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
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         ret = -EINVAL;
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         goto fail;
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     }
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+
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+    ret = validate_table_offset(bs, header.l1_table_offset,
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+                                header.l1_size, sizeof(uint64_t));
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+    if (ret < 0) {
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+        error_setg(errp, "Invalid L1 table offset");
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+        goto fail;
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+    }
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     s->l1_table_offset = header.l1_table_offset;
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+
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+
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     if (s->l1_size > 0) {
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         s->l1_table = g_malloc0(
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             align_offset(s->l1_size * sizeof(uint64_t), 512));
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diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080
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index 8a8b460..7255b6c 100755
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--- a/tests/qemu-iotests/080
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+++ b/tests/qemu-iotests/080
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@@ -45,6 +45,8 @@ _supported_os Linux
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 header_size=104
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 offset_backing_file_offset=8
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+offset_l1_size=36
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+offset_l1_table_offset=40
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 offset_refcount_table_offset=48
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 offset_refcount_table_clusters=56
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 offset_nb_snapshots=60
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@@ -117,6 +119,22 @@ poke_file "$TEST_IMG" "$offset_nb_snapshots" "\x00\x01\x00\x00"
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 { $QEMU_IMG snapshot -c test $TEST_IMG; } 2>&1 | _filter_testdir
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 { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+echo
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+echo "== Invalid L1 table =="
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+_make_test_img 64M
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+poke_file "$TEST_IMG" "$offset_l1_size" "\xff\xff\xff\xff"
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+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+poke_file "$TEST_IMG" "$offset_l1_size" "\x7f\xff\xff\xff"
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+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+
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+poke_file "$TEST_IMG" "$offset_l1_table_offset" "\x7f\xff\xff\xff\xff\xff\x00\x00"
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+poke_file "$TEST_IMG" "$offset_l1_size" "\x00\x00\xff\xff"
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+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+
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+poke_file "$TEST_IMG" "$offset_l1_table_offset" "\x12\x34\x56\x78\x90\xab\xcd\xef"
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+poke_file "$TEST_IMG" "$offset_l1_size" "\x00\x00\x00\x01"
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+{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
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+
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 # success, all done
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 echo "*** done"
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 rm -f $seq.full
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diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out
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index b06f47f..4ec2545 100644
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--- a/tests/qemu-iotests/080.out
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+++ b/tests/qemu-iotests/080.out
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@@ -47,4 +47,15 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
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 qemu-img: Could not create snapshot 'test': -27 (File too large)
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 read 512/512 bytes at offset 0
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 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
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+
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+== Invalid L1 table ==
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+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
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+qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
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+no file open, try 'help open'
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+qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
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+no file open, try 'help open'
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+qemu-io: can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
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+no file open, try 'help open'
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+qemu-io: can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
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+no file open, try 'help open'
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 *** done
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-- 
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1.7.1
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